I have been using arduino for awhile, but this is my first post in the forums. I have built a project that is working fine using the 6 data pins that I declare in my code:

LiquidCrystal lcd(7, 8, 9, 10, 11, 12);

but my senior partners and I in my class would like to imply more use of the Digital Pin outs especially the SPI pin outs, so I have decided to try the I2C route. Now I have connected Pin analog 4 (SDA ) and analog 5 (SDL) to the resepective Two wire interface for the board on the back of the 20 x 4 LCD as well as VCC and GND.

All the test code provided online doesn't work, I have arduino 1.0 and arduino 1.0.1 and it is kicking my @$$ on trying to get some readout on the LCD at all...I can get it to load using this code:

but the LCD just doesn't do anything......I know all about the ACK bit for the 7 / 8 bit transfer using I2C and the wire library needs to be included which it is.....

IS THERE ANYONE OUT THERE THAT HAS DONE a simple Arduino Uno to I2C LCD that could step me through some simple basics to get any readout on the 20 x 4 LCD...direct me to a proper library ...something....

the 4 wire harness I have is fine as well (Ohmed it out..) ...Pot for contrast is good too....

Scope yes.....I did try the pullups with 5K's and it still didn't work....I just want the LCD to display something.....I don't want my code written for me....am I not using the correct Libraries? I don't know....

simply..SDA and SDL are hooked up from arduino Uno to the I2C interface board behind the LCD...power and gnd are good...

is there any libraries I need beside LiquidCrystal_I2C and wire...

?

How do I know which address to use as well? I have seen a lot of 0x27 stuff

I was using the LiquidCrystal_I2C lcd( 0x27, 20, 4);

to initiate the LCD...i read how someone wrote you have to also code wire.begin but that just shows an error.